1. Technical Field
The present invention relates to a photographing apparatus that displays an image of a subject on a display unit.
2. Related Art
In the related art, a photographing apparatus that displays an image captured by a sensor on a display is known. In photographing apparatuses of recent years, a configuration in which an image processing is performed on a captured image and the image obtained by the image processing is displayed on a display is generally adopted. In this configuration, in order to prevent a delay before the image captured by the sensor is displayed on the display, various kinds of technique are developed. For example, in JP-A-2007-243615, a configuration that starts an image display on the display at a reproducing timing delayed by exactly ΔT from a driving timing of the sensor is disclosed.
In JP-A-9-307786, in order to reduce a circuit size and to reduce electromagnetic wave noise to be radiated, a configuration that drives the sensor and the display by an output signal of the same generator is disclosed. Furthermore, in JP-A-2011-158532, at a time of conflict when reading of image data and writing of image data conflict with each other, a configuration that avoids overtaking by slowing a clock cycle is disclosed.
In JP-A-2007-243615, a sensor and a display are driven by an output signal of separate clock generation units (clock generation unit 75 and clock generation circuit 27). In this manner, it is difficult to completely synchronize each clock signal generated by the separate clock generation units, and timings in a process of photographing and display are shifted relative to each other. Accordingly, even if the display and the sensor are driven at timings determined by each clock, and both of the timings are set so that the display is delayed by exactly ΔT with respect to the sensor, both of the driving times are shifted from an ideal timing in the process of photographing and display. As a result, it is difficult to maintain a state where the display is delayed by exactly ΔT with respect to the sensor, and a display delay longer than ΔT (for example, a delay of more than one frame) may occur as a result.
Although a configuration that drives the sensor and the display by the output signal of the same generator is disclosed in JP-A-9-307786, a configuration for preventing a display delay is not disclosed at all, in a configuration that displays an image captured by the sensor on the display after an image processing is performed in JP-A-9-307786. In JP-A-2011-158532, in a case where a conflict occurs regarding reading and writing of image data, there is a configuration that slows a reading speed during the reading of one line (FIG. 8 of JP-A-2011-158532). However, to assign a predetermined phase difference to the reading and the writing is not disclosed.